Using the method of density matrix, we get the rate equations about electron transport in the mesoscopic system derived form many body schrodinger equation. Makeing using of them, we obtain the spin current and charge current through the systems.

• 本文利用密度矩阵的方法，由多粒子体系的薛定谔方程，我们得到了微观体系中电子输运的几率方程，从而推导出通过量子点的自旋电流与电荷流的表达式。